If you live in San Francisco, you have yet another reason to pat yourself on the back: according to a recent survey of 3,750 people living in the 25 largest U.S. cities, San Franciscans are the least-wasteful people in the country. [via climatebiz]

Findings comes in the form of a study, sponsored by Nalgene as part of its America's Least Wasteful Cities campaign (ALWC), timed to coincide with "Earth Month," the increasingly long run-up to Earth Day, and aims to raise awareness of just how far we've come as a country to adopting green behaviors.

(A much-needed caveat: if we were to revisit my per capita trash post from earlier in March, we'd see that being the least-wasteful U.S. city, compared to waste levels in European countries as just one example, is about as proud an accomplishment as being the greenest mountaintop-removal coal-mining company.)

Caveats aside, the survey offers an interesting look at self-reported environmental behavior. The research firm Greenfield Online polled at least 150 residents of each of the biggest 25 cities in the country about their shopping, recycling, transportation, lifestyle and environmental outlook to gauge just how green these cities actually are.

Not surprisingly, San Francisco takes the cake, with an overall score of 1,025.45 points. New York City lands second prize with 1,004.01 points, and Portland, Ore., was the only other city to break the 1,000-point barrier, with 1,001.66 points.

The most-wasteful cities in the country is apparently Atlanta, with 857.51 points, with Dallas, Indianapolis and Houston bringing up the rear. Some of SF's proud accomplishments:

San Francisco's high rankings:• Recycling - 1st• Reusing wrapping paper - 1st• Turning off the water while brushing teeth - 1st• Avoiding driving for trips that are less than 2 miles from home- 1st• Using reusable containers in place of single-serve bottles of water/soda or other beverages - 2nd• Reusing zip-lock bags and tin foil - 2nd• Participating in their city's sustainability/environmental programs - 2nd• Using energy efficient light bulbs - 2nd• Saving leftovers and meals to eat again - 2nd• Buying bulk food to avoid extra packaging - 2nd• Taking public transportation - 2nd

SF fell short in just one category: for limiting showers to less than 5 minutes, the City by the Bay came in 12th.

For Atlanta, not a lot of notable successes; the city's residents came in fifth in composting and eighth in using rain barrels, but got a lot of last-place finishes as well:

Perhaps unsurprisingly, the U.S. West scored higher on average -- five cities ranked in the top: SF, Portland, Seattle, L.A. and Denver -- while the South and Midwest (which I just serendipitously typed "Midwaste") scored the lowest: Atlanta, Dallas, Indianapolis, Houston and St. Louis make up the bottom five cities.

Because these are all self-reported figures, they should be taken with a grain of salt, but there is an interesting inversion of the green halo that usually arises from these surveys (see Joel Makower's post, "Green Consumers' Irrational Exuberance," for more on this). But even though survey respondents in the more wasteful states overall ranked themselves lower, there remains a kind of green optimism throughout: one of the questions asked respondents if they planned to be more environmentally conscious in the next year. Who's going to respond no to that? In SF: only 9 percent didn't say yes (presumably because they're already green enough...); in New York City only 14 percent didn't say yes, and at the bottom of the charts 80 percent of Atlanta residents said they planned to do better next year.

In fact, only two cities' residents broke the 80 percent mark when asked if they planned to try harder: Houston (77 percent) and Phoenix (79 percent) were the least ambitious of the green cities.

The full rankings are on the next page; details about the survey and a handy map are online at LeastWastefulCities.com.

Here are the full rankings from Nalgene's America's Least Wasteful Cities campaign. Here is the explanation for how the scores are weighted, by way of the ALWC website:

To provide a better gauge of wastefulness or non-wastefulness, questions were then weighted, reasoning that some actions are have a higher influence on waste or overall impact on the environment. Each question was assigned a value of 1, 5, 10 or 25 by which the unweighted score was multiplied, providing the final, weighted score: